Officials are scrambling to build temporary bridges and detour roads for Colorado towns isolated by last week’s flooding. The race is on to get all the flooded towns road-accessible before heavy snows come later this autumn.

“Our primary focus is going to be on those communities that, frankly, only have one way in and out,” Amy Ford, a Colorado Department of Transportation spokesperson told NBC News. She added that transportation officials were getting creative and considering all options, including pontoon bridges and clearing rugged land to lay fresh roads.

Officials have to work quickly, before temperatures become too cold for pouring concrete or setting asphalt. “There’s a short window here before winter kicks in,” Ford said.

The flooding damaged 35 bridges and destroyed more than 100 miles of road.